Writing Pseudocode for Simple Algorithms

Pseudocode is a structured way of writing an algorithm in plain English before converting it into actual code. It helps programmers plan, organize, and visualize the steps of a program before implementation.

1. Pseudocode for Finding the Sum of Two Numbers

Problem Statement:

Write a pseudocode to take two numbers as input and display their sum.

Pseudocode:

BEGIN
   INPUT num1, num2
   SET sum = num1 + num2
   PRINT sum
END

Explanation:

• Take two inputs (num1 and num2).
• Perform addition and store the result in sum.
• Display the sum as output.

2. Pseudocode for Finding the Largest of Three Numbers

Problem Statement:

Write a pseudocode to find the largest among three numbers.

Pseudocode:

BEGIN
   INPUT num1, num2, num3
   IF num1 > num2 AND num1 > num3 THEN
      PRINT "num1 is the largest"
   ELSE IF num2 > num1 AND num2 > num3 THEN
      PRINT "num2 is the largest"
   ELSE
      PRINT "num3 is the largest"
   ENDIF
END

Explanation:

• Compare num1, num2, and num3.
• Print the largest number based on conditions.

3. Pseudocode for Checking if a Number is Even or Odd

Problem Statement:

Write a pseudocode to determine whether a number is even or odd.

Pseudocode:

BEGIN
   INPUT number
   IF number MOD 2 == 0 THEN
      PRINT "Even Number"
   ELSE
      PRINT "Odd Number"
   ENDIF
END

Explanation:

• Use the modulus operator (MOD 2) to check divisibility by 2.
• If remainder is 0, print "Even Number", otherwise print "Odd Number".

4. Pseudocode for Calculating Factorial of a Number

Problem Statement:

Write a pseudocode to calculate the factorial of a given number N.

Pseudocode:

BEGIN
   INPUT N
   SET factorial = 1
   FOR i FROM 1 TO N DO
      factorial = factorial * i
   ENDFOR
   PRINT factorial
END

Explanation:

• Multiply numbers from 1 to N to compute the factorial.
• Print the final value of factorial.

5. Pseudocode for Finding the Sum of First N Natural Numbers

Problem Statement:

Write a pseudocode to find the sum of the first N natural numbers.

Pseudocode:

BEGIN
   INPUT N
   SET sum = 0
   FOR i FROM 1 TO N DO
      sum = sum + i
   ENDFOR
   PRINT sum
END

Explanation:

• Initialize sum = 0.
• Use a loop to add numbers from 1 to N.
• Print the final sum.

6. Pseudocode for Checking if a Number is Prime

Problem Statement:

Write a pseudocode to check if a number N is prime.

Pseudocode:

BEGIN
   INPUT N
   SET isPrime = True
   IF N <= 1 THEN
      PRINT "Not Prime"
   ELSE
      FOR i FROM 2 TO N/2 DO
         IF N MOD i == 0 THEN
            SET isPrime = False
            BREAK
         ENDIF
      ENDFOR
      IF isPrime THEN
         PRINT "Prime Number"
      ELSE
         PRINT "Not Prime"
      ENDIF
   ENDIF
END

Explanation:

• Prime numbers are greater than 1 and divisible only by 1 and itself.
• Check divisibility for numbers from 2 to N/2.
• If N is divisible by any number in this range, it’s not prime.